Pressure fluid operable control valve



June 31 5, .1965 s. HECKMA'NN PRESSURE FLUID OIERABLE CONTROL VALVEFiled June 19, 1 961 INVENTOR. GU/VTEA HECKMflNN .is additionally ofdiiferent direction.

3,189,050 PRLSiURE FLUlD GKERABLE CGNTRGL VALVE Gunter Hechmann, SchultEnhrinlr 52, Sproclrhovel, Westphalia, Germany Filed June 19, 1961, Ser.No. 117,936

(Ilaims priority, application Germany, June 21, 1960,

H 39,723 6 Claims. (Cl. 137-625.63)

The present invention relates to a control valve for any type of fluidmeans, especially for compressed air, with single impulse reliefactuation, in which the respective impulse of any desired duration willadjust the main valve spool always in the respective opposite reversingposition.

Relief impulses are initiated for instance by a simple outlet valveoperable manually, mechanically, electromagnetically, pneumatically,hydraulically, or in any other possible manner. Such a relief valve maybe mounted on a control valve itself or remote therefrom. The valvespool may be provided with two, three or four pistons which according tothe threeor four-way principle may control the flow of fluid to amachine element on one or both sides, for instance a fluid pressurecylinder or a fluid pressure motor movable in one direction or inopposite directions.

Attempts have been made to solve this problem by preceding the controlvalve by a flutter valve (Flatterventil) in such a way that the reliefimpulse brings about a discharge of the pressure fluid to one or anotherflutter valve branch and thereby moves the valve to the outlet seatwhereby in the other branch of the flutter valve the fluid medium iscontrolled with the result that the valve spool is reversed. This typeof control works, however, only at a predetermined pressure inasmuch asit is dependent to a high extent on the respective cross section. Inother words, this type of control will frequently respond already tosmall accumulations of soil, to leakages or to displacements oflubricants. This known control is, therefore, suitable only for controlwork where the emphasis is more on saving control conduits rather thanon-a safe operation and on avoiding reverse control operations.

This known control functions only at short strokes of the workingcylinder to be controlled because the pressure fluid to be distributedthrough the flutter valve is controlled by the control valve in thefeeding line to the machine element. This known control, therefore,causes already at passages which are deliberately held small a newnon-controllable relief impulse upon the flutter valve. This isparticularly the case when the relief impulse Moreover, this control issuitable only for compressed air.

Other control valves which by means of single relief impulses move thevalve spool in the respective opposite positions have not been knownheretofore.

It is, therefore, an object of the present invention to provide acontrol valve which will overcome the above mentioned drawbacks.

It is another object of this invention to provide a control valve whichin an absolutely safe manner will assure a single impulse reliefcontrol.

These and other objects and advantages of the inven tion will appearmore clearly from the following specification in connection with theaccompanying drawing in which:

FIG. 1 illustrates a longitudinal section through a first United StatesPatent 0 embodiment of a control valve according to the presentinvention.

FIG. 2 is a longitudinal section through a modified control valveaccording to the present invention.

The objects of the present invention have been realized "ice primarilyin that the main control valvehas associated therewith an auxiliaryvalve spool which is adapted alternately to effect communication betweenthe relief conduits on the left-hand and right-hand side of the mainvalve spool with a relief means, for instance a discharge valve adaptedto be actuated by any desired means. The said auxiliary valve spool iscontrolled and held in its reversing positions by a pressure fluidmedium alternately reversed by the main valve spool and passed into thepressure fluid conduits which are branching off from the working path ofthe main valve spool. The respective reversal of the auxiliary valvespool may in spite of the pressure fluid prevailing at the respectivepoint be effected only when the relief conduit has again been closed.This is brought about by permitting the pressure fluid medium which isintended to adjust the auxiliary valve spool for the next followingrelief operation and the flow of which to the auxiliary valve spool iscontrolled by the main valve spool, to flow off through a check valveand through the relief impulse conduit as long as the relief impulsewill last. Only after the relief impulse has ended, the pressureintended for reversing the auxiliary valve spool or pre-control membercan build up. trol, any reversal of the main control valve spool will bemade impossible. It is for this reason that already the first tests haveresulted in more than 50,000 fault free sequential controls.

Control valves according to the present invention are particularlysuitable for use in connection with electromagnetic valves. This is dueto the fact that the control valve according to the present inventionwill for purposes of initiating impulses operate with the smallest knownelectromagnetic valves at cross sections of a diameter of a fewmillimeters up to the greatest practically occurring diameters. Anelectromagnet with a 15% duration of lead application in form of asimple alternating current or direct current magnet will sufiice foractuating the valve according to the present invention so that whenemploying alternating current, the heretofore customary rectifier willbecome superfluous because permanent magnet switch operations will notbe requir ed any longer. The possible control frequency has furthermore,when employing compressed air, proved enormously high so that the reliefimpulses may be very short. However, the fact that the auxiliary valvespool will be reversed only after the relief impulse for the nextfollowing impulse has been completed, will make possible an impulseduration which is not limited as to time as this is possible forinstance with impulse emitters, as

for example a nut on a threaded spindle which nut is to be stopped inthe very position in which it releases the impulse. Such an arrangementprevails with mechanically actuated relief valves used in connectionwith a rope winding device.

Referring now to the drawing in detail and FIG. 1 thereof in particular,this figure shows a practical embodiment of the present invention whichhas proved highly successful. The control valve illustrated in FIG. 1comprises a housing 14 having reciprocably mounted therein a four-pistonvalve spool 17. The pressure fluid enters at 26 into the piston annularchamber 18 and is passed through bores 24, the central piston bore 23and bores 25 into the annular chamber 2%}. In addition thereto, thepressure fluid passes through relatively narrow bores 15a, 16a in thevalve spool end faces 15, 16 to both sides of the valve spool into thechambers 21 and 22. In the particular position shown in the drawing, thevalve spool 17 establishes communication between the pressure fluidinlet 26 and the passage 27 leading to the device to be controlled andthe outlet 28. The outlet connection 1 in the pre-control housing 3 orthe housing for the. auxiliary Patented June 15, 1965 In view of thisautomatic sequence of con- .15 valve spool and the outlet connections 30and 31 in the main housing 14 have connected thereto conduits 1a, 33 and34 which have arranged therein for instance simple discharge valves A, Band C. Normally, the valves A, B and C are closed.

Small conduit 11 leads from the annular chamber 18 of the valve spool tothe right hand end of the bore in housing 3, while small conduit leadsfrom the annular chamber 19 of the valve spool to the left end of thebore in housing 3.

The operation of the valve of FIG. 1 according to the present inventionis as follows:

When the shutoff valve A mounted in the impulse conduit 1a isopened-said valve A acting in this instance as impulse producingvalve-pressure fluid will pass from the chamber 22 at the right-handside of housing 22 (with regard to FIG. 1) .through the relief passage13 into the annular chamber 8 of the pre-control valve spool 2 and fromthere through connection and valve A into the conduit 1a. This willcause a sudden pressure drop in chamber 22 because the quantity ofpressure fluid which at this time can pass through the small bore 16a ofthe valve spool 17 into chamber 22 is only very small and, therefore,cannot make up the pressure lost from chamber 22 on account of the justdescribed passage of fluid from the chamber 22 into conduit 1a. Thissituation creates a substantial pressure difference between chamber 21and chamber 22, the pressure in chamber 21 being maintained by theoncoming pressure fluid passing through the bore a of the valve spool17. Valve spool 17 is thus caused to move toward the right in thedirection toward the lid 14a. While previously the small branch conduit11 was conveying pressure fluid and thereby held the pre-control valvespool 2 in its left-hand end position, whereas in this instance thebranch conduit 10 communicated with the exhaust chamber 19, the twosmall branch conduits 10 and 11 will have their functions reversed whenthe main valve spool 17 has moved toward the right. The annular chamberwill then convey pressure fluid to the machine element to be actuatedwhereas the annular chamber 19 will then establish communication betweenconduit 27 and exhaust 28. Thus, the branch conduit 10 Will conveypressure fluid while the branch conduit 11 communicates with the exhaust28. The pressure fluid which passes through the relatively narrowconduit 10 will through bore Sin the pre-control valve spool 2 move thecheck valve ball 4' toward the right with regard to FIG. 1 to such anextent that the pressure fluid entering through conduit 10 will passthrough small bores 7 of valve spool 2 and its annular chamber 8 intothe impulse conduit 1a. This condition will be absolutely stable andwill remain table as long as the shut-off valve A is in its openposition.

If valve A and thereby conduit 1a is again closed, pressure will buildup in theannular chamber 8 of the precontrol valve spool. This pressurewill act upon the check valve ball 4 and press the latter onto itsright-hand seat 6. As a result thereof, the pressure acting upon theleft-hand end face of the valve spool 2 will move the latter into itsright-hand end position. The pressure prevail-- ing in conduit 10 andacting on the right-hand side of valve spool 2 will maintain thiscondition stable, iLe. will maintain valve spool 2 in its right-handposition because now also branch conduit 11 communicates with theexhaust and thus maintains the right-hand end face of valve spool 2pressure-less. Consequently, the valve spool 2 maintains the reliefpassage 13 closed whereas the relief passage 12 will now communicatewith annular chamber 8 of valve spool 2 and thereby will alsocommunicate with the impulse passage 1a. The entire arrangement is nowready for the next relief impulse which when initiated will bring themain valve spool 17 and also the pre-control valve spool 2 back into theposition shown in FIG. 1.

The main valve spool 17 will shortly before reaching its end positionmove over the relief passage 12 or 13 for cushioning purposes only. Thehousing 14 may with this relief impulse control additionally be providedwith two further relief connections 30 and 31 for special successive orsafety control steps. The said two relief connections 30 and 31 whencommunicating with corresponding conduits bring about that the mainvalve spool is either displaced, as would be the case for instance whena relief impulse is conveyed through connection 30, or that for acertain control condition the main valve spool 17 will move into theproper position pertaining to said certain control condition. This maybe the case when the relief would be effected through the connection 31.For this possibility, there may by way of example be mentioned a remotecontrolled switch adjusting device as it is actuated for instance by atravelling train in mining operations. In such an instance, theadditional relief connections 30 and 31 are important because they couldthen always be automatically actuated in a simple manner when the trainpasses from a branch track through the switch to the main track. In suchan instance the switch will safely be adjusted in the correct manner orwill not be adjusted at all if it is already in its proper position. Thevalves B and C in conduits 33 and 34 provide for the above-mentionedcontrol possibilities and are thus auxiliary impulse control meansremote from valve A.

The fundamental principle underlying the control valve of the presentinvention may, of course, be varied as shown for instance in FIG. 2.According to this last mentioned embodiment, the valve spool 2 isreplaced by a piston which, however, may also be replaced by other meansas for instance a diaphragm.

With reference to FIG. 2, a one-step piston 2a is reciprocably mountedin housing 3 and is freely movable between two intermediate wallsprovided with bores 5a and 6a. This piston when occupying the positionshown in the drawing covers the relief conduit 12 whereas the reliefconduit 13 communicates through its right-hand free cylinder chamber andbore 6a and the chamber 8a through a check valve 4a with the impulseconnection 1a. The branch conduit 11 which in this position is underpressure, likewise leads into chamber 8a, whereas the left-hand pistonend face communicates through bore 5a, chamber 7a and branch conduit 10with the exhaust 28. Thus, also in this instance the pressure fluidmaintains the piston 2a in its left-hand position, and this position isabsolutely stable.

If now a relief impulse is brought about at the connection 1a, therelief conduit 13 is relieved in the manner described above and the maincontrol valve spool 17 will in conformity with the description of thearrangement of FIG. 1 be moved into its right-hand reversing position.In this way, also the function of the branch conduits 10 and 11 isreversed while pressure fluid passes through passage 1t) and is conveyedto the impulse connection 1a through the intervention of the easilymovable check valve 411. The branch conduit 1 1 communicates with theexhaust 28.

Thus, also with this arrangement the decisive position of the entiredevice is stable. Furthermore, also in this instzmce the piston 2a canmove into its right-hand reversing position only after the impulseconduit connected to connection 1a has been closed because only then itwill be possible to build up the necessary pressure for initiating tEnext impulse. It will thus be evident that the embodiment of FIG. 2 asfar as its function is concerned fully corresponds to that of FIG. 1.The embodiment of FIG. 2 has the further advantage that it isstructurally simpler and that the relief passages or conduits or branchconduits will not have to cross each other.

The control valve according to the present invention is particularlysuitable for all control operations, especially where the control valveis to be actuated remote from its effective location because in allthese instances merely one relief conduit or one electric conduit isrequired. This is the case for instance with remote controlled largeshutoff valves, switch control devices, door actuating means,pneumatically, hydraulically or electrically operated cart pullingdevices in mines where the control is advantageously arranged notbetween the rails of a mine track but at the joint or on the oilcontainer.

A further essential advantage of the control valve according to thepresent invention consists in that it will operate independently of thecross section and of the length of the conduits leading to the devicesto be controlled.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular constructions shown in the drawings butalso comprises any modifications within the scope of the appendedclaims. Thus,

the main valve spool may also be replaced by a two-step V or three-steppiston or may be designed as flat or rotary valve member or may functionas valve system in combination with the pre-oontrol arrangementaccording to the present invention.

What Iclaim is:

1. In a control valve, a main housing having a pressure fluid inlet andan outlet, a main control member having end faces and reciprocableinsaid housing between first and second end position-s, the end faces ofsaid main control member respectively confining with said housing afirst and a second end chamber, throttle means establishing a throttledcommunication between said pressure fluid inlet and said first andsecond end chambers, said housing also being provided with two reliefpassage means respectively communicating with said first and second endchambers, an auxiliary housing having an impulse outlet for connectionwith an impulse relief conduit, an auxiliary control member reciprocablewithin said auxiliary housing and forming therewith a pair of auxiliaryend chambers, said auxiliary contnol memberbeing moveab-l-e from .afirst position into a second position and vice versa in said auxiliaryhousing for respectively establishing communication between one of saidrelief passage means .and said impulse outlet While interruptingcommunication between the other relief passage means and said impulseoutlet, a

conduit leading from each said end chamber of said auxil iary housing,said main control member in one end position connecting one of saidconduits to said fluid inlet and the other thereof to said outlet and inthe other end position connecting said other conduit to said fluid inletwhile connecting said one conduit to said outlet, channel meansrespectively connecting the chambers of said pair of auxiliary endchambers with sa-idimpulse conduit, check valve means preventing directcommunication between the chambers of said pair of auxiliary endchambers, and a valve controlling said impulse relief conduit.

2. In a control valve, a main housing having a pressure fluid inlet andan exhaust and also having a first port and a second port, a main valvespool having end faces and reciprocable in said housing between firstand second positions, said main valve spool including a plurality' ofcontrol chamber means operable in one end position of said main valvespool to establish communication between said first port and saidpressure fluid inlet while simultaneously establishing communicationbetween said second port and said exhaust, said control chamber meansalso being operable in response to said main valve spool occupying itsother end position to' establish communication between said second portand said pressure fluid inlet while simultaneously establishingcommunication between said first port and said exhaust, the end faces ofsaid main valve spool respectively confining with said housing a firstand a-second end chamber, throttle means establishing a throttledcommunication between said pressure fluid inlet and said first andsecond end chambers, said housing also being provided with two reliefpassage means respectively communicating with said first and second endchambers, an auxiliary housing having an impulse outlet forcommunication with an impulse relief conduit, an auxiliary controlmember having two oppositely located effective surfaces and beingmovable within said auxiliary housing from a first position into asecond position and vice versa for respectively establishingcommunication between one or the other of said relief passage meanswith'said impulse outlet, first and second additional conduit meansrespectively connecting one of said effective surfaces of said auxiliarycontrol member with one of said control chamber means and the othereffective surface with another of said control chamber means in one endposition of said main valve spool and reversing said connections in theother end position of said main valve spool, passage means leading fromsaid effective surfaces to said impulse outlet, check valve meanspreventing fluid flow from said impulse outlet to said eifectivesurfaces while permitting fluid flow from said effective surfaces tosaid impulse outlet, and a valve operable for controlling said impulseconduit.

3. A control valve according to claim 1, in which said auxiliary controlmember is a one-step piston.

4. In a control valve, a main housing having a pressure fluid inlet andan outlet, a main valve spool having end faces and reciprocable in'saidhousing between first and second end positions, the end faces of saidmain valve spool respectively confining with said housing a T first anda second end chamber, throttle means establishing a throttledcommunication between said pressure fluid inlet and said first andsecond end chambers, said housing also being provided with two reliefpassage mean-s respectively communicating with said first and second endchambers, an auxiliary housing having an impulse outlet for connectionwith an impulse relief conduit, said auxiliary housing including a boreand also including first and second fluid conveying means at oppositeends of said bore, conduit means leading from said fluid conveying meansand alternately connected to said fluid inlet and said outlet inresponse to movement of said main valve spool from one end positionthereof to the other, said auxiliary housing furthermore including checkvalve means permitting fluid flow from said fluid conveying means tosaid outlet while preventing fluidflow in the opposite direction, pistonmeans reciprocable within said bore from a first position into a secondposition and vice versa in response to fluid pressure in respective onesof said fluid conveying means for respectively establishing andinterrupting communication between said relief passage means and saidfluid conveying means, and a valve in said impulse relief conduitoperable for selectively opening and closing said conduit.

5. A valve according to claim 1, which includes auxiliary impulsecontrol means arranged remote from said impulse outlet for controllingsaid main control member.

6. A control valve according to claim 1, in which each said reliefpassage means leads into the pertaining said end chambers at a pointtherein such that the respective relief passage means will be covered bythe respective adjacent end portion of said main control member in itsrespective adjacent end position whereby a cushion chamber remains insaid end chamber in the respective adjacent end position of said maincontrol member while movement of the main control member toward itsother end position will uncover the said covered relief passage means.

References Cited by the Examiner UNITED STATES PATENTS 2,709,421 5/55Avery 91-51 XR 2,867,191 1/59 Herrmann 12117 2,912,008 11/59 Blackburn137--625.62 XR 2,939,430 6/60 Westbury 137--625.62 XR 3,012,575 12/61Woody et a1. 137-62562 3,113,590 12/63 Olson 137--625.6

FOREIGN PATENTS 80,214 12/55 Holland. 146,983 12/54 Sweden.

MARTIN P. SCHWADRON, Acting Primary Examiner.

KARL I ALBRECHT, M. CARY NELSON, Examiners.

1. IN A CONTROL VALVE, A MAIN HOUSING HAVING A PRESSURE FLUID INLET ANDAND OUTLET, A MAIN CONTROL MEMBER HAVING END FACES AND RECIPROCABLE INSAID HOUSING BETWEEN FIRST AND SECOND END POSITIONS, THE END FACES OFSAID MAIN CONTROL MEMBER RESPECTIVELY CONFINING WITH SAID HOUSING AFIRST AND SECOND END CHAMBER, THROTTLE MEANS ESTABLISHING A THROTTLEDCOMMUNICATION BETWEEN SAID PRESSURE FLUID INLET AND SAID FIRST ANDSECOND END CHAMBERS, SAID HOUSING ALSO BEING PROVIDED WITH SAID RELIEFPASSAGE MEANS RESPECTIVELY COMMUNICATING WITH SAID FIRST AND SECOND ENDCHAMBERS, AN AUXILIARY HOUSING HAVING AN IMPULSE OUTLET FOR CONNECTIONWITH AN IMPULSE RELIEF CONDUIT, AN AUXILIARY CONTROL MEMBER RECIPROCABLEWITHIN SAID AUXILIARY HOUSING AND FORMING THEREWITH A PAIR OF AUXILIARYEND CHAMBERS, SAID AUXILIARY CONTROL MEMBER BEING MOVABLE FROM A FIRSTPOSITION INTO A SECOND POSITION AND VICE VERSA IN SAID